One of Manchester United or Manchester City will be forced to play two games in three days at the end of October -- one being their Premier League derby -- after both were drawn at home in the Capital One Cup fourth round.
United and City never play at home on the same night because of policing issues, but one of them is set for a intense run of fixtures soon after next month's international break.
Therefore, one will have to face a second fixture little more than 48 hours after their top-of-the-table clash, potentially forcing Louis van Gaal or Manuel Pellegrini to select a weakened team in the Capital One Cup.
United will meet Championship promotion contenders Middlesbrough while City take on Premier League rivals Crystal Palace.
One match will be played on Tuesday, Oct. 27 -- two days after the derby -- and the other on Wednesday, Oct. 28.
United and City meet at Old Trafford on Oct. 25 while both are in Premier League action six days later, when City host Norwich and United visit Crystal Palace.
Neither match can be shifted back to the Sunday because both have Champions League games on Nov. 3.
Both Van Gaal and Pellegrini selected strong sides in their third-round victories.
City's Chilean coach omitted only Fernandinho of his fit first-team players as they won 4-1 at Sunderland, while Dutch boss Van Gaal arguably picked eight of his preferred starting XI as Ipswich were defeated 3-0.